Advances in technology have provided the medical practitioner with a variety of medical imaging systems. One important class of medical imaging systems works by radiating energy through a region of interest in the body, either from an external source, such as x-rays or an RF field, or from an internal source such as an injected radioisotope. The interaction of the radiated energy with the body is measured at a variety of small volume elements ("voxels") within the body. The spatial coordinates of each of these voxels are identified and a map of the body within that region of interest is developed.
Two important types of medical imaging systems which provide such voxel data are Magnetic Resonance Imaging ("MRI") and X-ray Computed Tomography ("CT").